The Effect of Socioeconomic Status on the Development of Non-alcoholic Steatohepatitis: Findings From the National Health and Nutrition Examination Survey (NHANES)

Abstract

Introduction: Nonalcoholic Steatohepatitis (NASH) is a major public burden in the US and the third leading indication for liver transplantation. Lifestyle and dietary alterations have been explored and used as first line of treatment. However, the contribution of socioeconomic factors to the prevalence NASH has not been adequately explored. Methods: This is a cross sectional study using the NHANES III database. Patients were included if they had NASH: Fatty liver on ultrasound, elevated liver enzymes, negative serology for Hepatitis B and C and alcohol consumption of < 20 grams/day for men and 10 grams/day for women. Socio-demographic and medical information was abstracted from the appropriate files in NHANES III. A multivariate regression analysis model was built to measure the independent contribution of each predictor studied to the prevalence of NASH. The model included known NASH risk factors (age, sex, obesity and Diabetes Mellitus (DM)) in addition to food security, income level, education, household size, marital status, and urban/rural residence location. Results: 46,231 participants met the criteria for NASH and included in the final analysis. On multivariate analysis, there was no significant associations between gender, age and NASH. All adjusted odds ratios (aOR) are presented in Table 1. Obesity was associated with a 5-fold (95% confidence interval (CI): 1.47-18.28, P=0.01) increase in the odds of NASH. Food security, household size, marital status and reaching a 12th grade level of education had no significant association with NASH. However, poverty was an independent risk factor for NASH. Compared to those whose income was below the federal poverty level (FPL), participants with income between 100% to 200% of FPL had similar and those with an income above 200% of FPL had significantly lower odds of NASH. (aOR: 0.19, 95% CI: 0.04-0.93, P=0.04). In addition, living in counties with less than 1 million population was strongly protective against NASH (aOR: 0.17, 95% CI: 0.08-0.35, P < 0.01).Table: Table. Multivariate AnalysisConclusion: Our findings demonstrate an association between socioeconomic status and the prevalence of NASH. This association is largely independent of other known risk factors like obesity and Diabetes Mellitus. The association between NASH prevalence and living in dense counties is much stronger than that of income level and food security. Therefore, further research is needed to explore the possible role of neighborhood and environmental factors in the prevalence of NASH.